[previous] MISRA-C:2004  Rule  19.17:  (Required) [next] All #else, #elif and #endif preprocessor directives shall reside in the same file as the #if or #ifdef directive to which they are related.
When the inclusion and exclusion of blocks of statements is controlled by a series of preprocessor directives, confusion can arise if all of the relevant directives do not occur within one file. This rule requires that all preprocessor directives in a sequence of the form #if / #ifdef ... #elif ... #else ... #endif shall reside in the same file. Observance of this rule preserves good code structure and avoids maintenance problems.

Notice that this does not preclude the possibility that such directives may exist within included files so long as all directives that relate to the same sequence are located in one file.

file.c 

#define A
...
#ifdef A
...
#include "file1.h"
#
#endif
...
#if 1
#include "file2.h"
...
EOF

file1.h 

#if 1
...
#endif                        /* Compliant */
EOF

file2.h 

...
#endif                        /* Not compliant */

QAC messages that encompass this guideline:

3317 '#if...' not matched by '#endif' in included file. This is probably an error.
3318 '#else'/'#elif'/'#endif' in included file matched '#if...' in parent file. This is probably an error.


(c) The Motor Industry Research Association, 2004
QA C Source Code Analyser 8.1.2
MISRA-C:2004 Compliance Module 3.2
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